A malfunctioning vape likely exploded and set a bedroom on fire in Barr St, Kenmure, leaving a Dunedin person with burns to their hands on July 6.
Fire and Emergency New Zealand (Fenz) received a call to the property, which had no working smoke alarms.
At the time, Fenz fire investigator Matt Jones said the fire could have potentially been fatal.
A fire investigation report released to the Otago Daily Times under the Official Information Act showed the fire was most likely accidentally caused by a vape possibly exploding while laying on a bed in a downstairs bedroom.
The report said the entry to the bedroom where the fire broke out was partially burnt and dislodged from its frame, and within the room was a heater, dehumidifier, a wet/dry vacuum and a bike.
"The bed was completely consumed by fire — notably, a multi-board and a vape device were located near the bed area," the report said.
The most intense charring was located on the ceiling above the bed, indicating this was where there was the greatest flame and heat activity.
The upper floor of the property was less damaged, but the hallway and room next to the bedroom were smoke and heat damaged.
Mr Jones said electronics such as laptops, vapes and cellphones should not be left on beds or couches while charging, as they could build up heat on soft surfaces and cause the fabric to catch fire.
One resident of the property was also burnt in the fire while escaping.
The investigation found the fire most likely started on a three-seater couch on the porch.
"Based on the evidence available at the time of the investigation ... this incident has been recorded as an accidental fire caused by an open-flame device such as a cigarette lighter, match, candle or smoking device."
The fire spread from outside in and consumed all rooms, the entire roof and eventually engulfed the entire structure.
Every single room sustained significant damage, leading to the Dunedin City Council condemning the building as unsafe and demolishing it.
All the contents inside the home were destroyed.
